(Supersedes Service Instruction No. 1425) DATE: January 19, 1988 MODELS AFFECTED All Textron Lycoming Reciprocating Engines. TIME OF COMPLIANCE As required. Field experience has shown that engine oil contamination increases the possibility of sticking and/or stuck valves. This situation occurs when the contaminants in the engine lubrication oil become deposited on the valve stems, restricting the...

DATE: August 15, 1986 MODELS AFFECTED All Avco Lycoming Direct Drive Engines. TIME OF COMPLIANCE Each 100 hour inspection. During each 100 hour inspection, Avco Lycoming Textron recommends the use of one of two methods for checking alignment of engine timing marks prior to timing magneto to engine.

DATE: April 25, 1986 MODELS AFFECTED Avco Lycoming Direct Drive Engines. TIME OF COMPLIANCE At next overhaul or earlier at owner's discretion. A change from constant speed to fixed pitch and vice versa dictates a change in model designation. Replacement nameplates are only issued if the original nameplate is lost. Refer to the latest edition of Service Instruction No. 1304. Engines may be changed...

DATE: July 30, 1976 MODELS AFFECTED O-235; O-290; O, IO, AIO, AEIO, LIO-320 series; O, IO, AIO, AEIO, HIO, LIO-360 series; O-540 series except dual magneto models identified by “D” as 5th character in model designation; IO, AEIO-540 series except IO-540- E1A5, -K1B5, -K1E5, -P1A5, -S1A5 using large volume oil pump and dual magneto models. TIME OF COMPLIANCE At next overhaul. Positive lubrication...

Supersedes Service Instruction No. 1193 DATE: June 12,1970 TIME OF COMPLIANCE As required. In some instances, when a valve or one of its related parts is replaced because of failure, a subsequent failure of the same part is experienced. This is the result of neglecting to determine the cause of failure. For example, the failure of avalve canbe causedby installation ofapush rod of incorrect length...

Supersedes Service Instruction No. 1047A DATE: November 24, 1967 MODELS AFFECTED All Avco Lycoming engines with nitride hardened steel cylinder barrels. TIME OF COMPLIANCE During overhaul of the engine. Many Avco Lycoming engines are presently manufactured with cylinder assemblies that incorporate nitride hardened steel cylinder barrels. Because this cylinder barrel surface is hardened, the repair...

This article is the first of three that explains in more detail Lycoming Engines's position on automotive fuels. The bottom line is that it's possible to make automotive gasoline "fitfor-purpose" for aviation. However, in doing so, you deviate from "pump gas" and end up creating a low octane unleaded aviation fuel from automotive gasoline blend stock - "mogas." Why do we need to have fuels "fit...

Automotive fuel from the pump is NOT the same everywhere you go. There are summer blends, winter blends, geographical blends within the seasonal changes, varying levels and types of oxygenates (not just ethanol) and when tanks are switched over a mixture of "in between". The pump labeling is accurate for octane, and in some parts of the world, the maximum percentage of ethanol. It doesn't tell you...

Lycoming tests every engine that rolls off our assembly line. We take them into one of our test cells, attach a propeller and appropriate sensors, and then operate them through a range of tests. These tests can last from an hour up to four hours. We also use our test cells to evaluate components and new products. Every year we do this for about 3000-4000 engines. Lycoming purchases and consumes a...